I have expanded on this further, found a tastier name and now have a project page up http://projects.cyberlot.net/trac/jqpie/wiki. Added an cheesy jQuery/Interface autocomplete example although I would of preferred a json approach to the xml but it works never the less.

The jQPie project provides a way to link Javascript and PHP easily through the jQuery library with simple requests to use things JSON statements and direct output in your Javascript application.